This invention relates generally to packaged integrated electronic circuits. More particularly, this invention relates to sensing the orientation of a packaged IC in a socket.
Very Large Scale Integrated (VLSI) chips may contain millions of transistors and electrical connections. Because VLSI chips may be so complex, a great deal of testing may be required to verify that a particular chip is fully functional. The time required to test an integrated circuit (IC) may increase the cost of an IC. As a result, it is desirable to reduce the time required to test an IC.
ICs are typically manufactured on a silicon wafer. Each silicon wafer may contain dozens of individual ICs. These ICs may be microprocessors, DRAMs (Dynamic Random Access Memory), SRAMs (Static Random Access Memory), or other types of ICs. The individual ICs on a silicon wafer are usually tested before the wafer is cut into separate, individual ICs. After all the ICs on the wafer are tested, the wafer is cut into separate, individual ICs and the ICs that passed the tests during wafer test are packaged.
Next, packaged ICs are tested. Packaged ICs are usually placed in a socket that is connected to external test equipment. The external test equipment applies power and signals to operate and test packaged ICs. The tests applied by test equipment can be very complex and as a result may require a relatively great deal of time to complete testing. Before applying the complete suite of tests found on external test equipment, it would be helpful to know if the packaged IC is correctly oriented in a test socket.
The orientation of a packaged IC may be difficult to detect, for example, because the module may be symmetrical about both the X and Y axis. As a result the packaged IC may be incorrectly placed in a socket. If a packaged IC is incorrectly placed in a socket during testing of the packaged IC, the tests may fail and a great deal of time and effort may be used before it is discovered the packaged IC is incorrectly oriented in the socket.
In addition, when a packaged IC is incorrectly oriented in a socket that is part of a system, for example, a computer, the system may not operate properly. Again, a great deal of time and effort may be used in this situation before the incorrect orientation is detected.
There is a need in the art to communicate the orientation of a packaged IC in a socket. One embodiment of this invention communicates the orientation of a packaged IC in a socket by activating an LED mounted to the socket when the orientation of the packaged IC is incorrect. A detailed description of this embodiment of this invention is described later.
An embodiment of this invention provides a system and method for indicating the orientation of a packaged IC in a socket. An LED is physically mounted to a socket. One lead of the LED is electrically connected to a positive voltage through a socket hole on the socket. When the orientation of the IC package in the socket is correct, the other lead of the LED is connected to a ground path on the packaged IC. As a result, the LED is activated indicating the orientation of the packaged IC is correct.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawing, illustrating by way of example the principles of the invention.